Ph_3PO和N_(1923)协同萃取金(Ⅲ)的研究

Studies on the Synergistic Extraction of Gold( Ⅲ) with N_1923 and Ph_3PO

近年来,对萃取金的研究已有较多报道,而协同萃取金的研究却较少。Miller指出,胺和中性膦氧化物的混合体系可以有效地提高从氰化物中萃取金和分离金、铜的能力,但没有讨论其协同萃取机理。我们在此基础上,选用三苯基氧膦(Ph_3PO)和伯胺N_(1923)作为协同萃取金的混合萃取荆,详细考察了多种因素对其从氯化物介质中协同萃取金(Ⅲ)的影响,确定了协萃配合物的组成,并对协同萃取机理进行了探讨。

The synergistic effect of the extraction of Au( Ⅲ) from HCl medium with N1923 (primary amine)-Ph3PO in CHC13 was investigated. The effects of the concentration of AuCl4- Cl- and H+ ions in aqueous phase and that of Ph3PO and N1923 in the organic phase on the synergistic extraction of Au( Ⅲ ) with N1923-Ph2PO-CHCl3 were studied respectively by the slope method. The results show that the synergistic mechanism of this system may be represented byAuCl4-+N1923 · HCl(0) + 3Ph3PO(0) KNT(3Ph3PO· N1923 · H+) · AuCl4-(0)+Cl-The equilibrium constant KNT is 107.92(at 25 ℃). The mechanism was proved further by the methods of UV spectra and molar conductance determination. IR spectra show that there is N-H-O hydrogen bond in the synergistic species(3Ph8PO · N1923 · HAuCl4.